The learning curve in endoscopic transsphenoidal skull-base surgery: a systematic review

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) has revolutionized skull-base surgery; however, it is associated with a steep learning curve (LC), necessitating additional attention from surgeons to ensure patient safety and surgical efficacy. The current literature is constrained by the small sample sizes of studies and their observational nature. This systematic review aims to evaluate the literature and identify strengths and weaknesses related to the assessment of EETA-LC.

METHODS

A systematic review was conducted following the PRISMA guidelines. PubMed and Google Scholar were searched for clinical studies on EETA-LC using detailed search strategies, including pertinent keywords and Medical Subject Headings. The selection criteria included studies comparing the outcomes of skull-base surgeries involving pure EETA in the early and late stages of surgeons' experience, studies that assessed the learning curve of at least one surgical parameter, and articles published in English.

RESULTS

The systematic review identified 34 studies encompassing 5,648 patients published between 2002 and 2022, focusing on the EETA learning curve. Most studies were retrospective cohort designs (88%). Various patient assortment methods were noted, including group-based and case-based analyses. Statistical analyses included descriptive and comparative methods, along with regression analyses and curve modeling techniques. Pituitary adenoma (PA) being the most studied pathology (82%). Among the evaluated variables, improvements in outcomes across variables like EC, OT, postoperative CSF leak, and GTR. Overcoming the initial EETA learning curve was associated with sustained outcome improvements, with a median estimated case requirement of 32, ranging from 9 to 120 cases. These findings underscore the complexity of EETA-LC assessment and the importance of sustained outcome improvement as a marker of proficiency.

CONCLUSIONS

The review highlights the complexity of assessing the learning curve in EETA and underscores the need for standardized reporting and prospective studies to enhance the reliability of findings and guide clinical practice effectively.

3-Dimensionally Printed Affordable Nose Model: A Reliable Start in Endoscopic Training for Young Neurosurgeons

BACKGROUND

Training neurosurgical skills is one of the most important tasks of a residency program. Techniques' complexity and pathology rarity define a long learning curve for mastering different surgical skills for which simulation on anatomic samples is extremely important. For this purpose, cadaver laboratory training is the most reliable tool. However, since access to cadaveric specimens is limited, due to costs and availability, surgical skills could be developed using inanimate models. This work aimed to develop a printable 3-dimensional model of the nasal cavity and sellar floor using an open-source downloadable file, to give residents the opportunity to improve their endoscopic surgical skills in a low-risk atmosphere with little cost.

METHODS

The 3D model was realized taking as a sample a real-case CT scan imaging from which the sellar floor was removed. A quail egg was placed underneath the printed model covering the sellar floor opening. Under endoscopic visualization, the "sellar floor" was drilled by each participant with the goal of sparing the egg's inner membrane. Once the task was achieved, surgeons were asked to participate in a satisfaction survey.

RESULTS

The total cost for printing was 6.31€ (6,72$). A satisfaction survey showed technical improvement (90%), increased confidence (80%), and bringing learned skills into the operating room (70%), leading to a 100% agreement in introducing this project into residency programs.

CONCLUSIONS

Training on affordable anatomic models represents a useful tool in technical skills improvement. We believe this model could help residents bring their technical capabilities to more sophisticated levels.

Endoscopic transsphenoidal surgery for non-functioning pituitary adenoma: Learning curve and surgical results in a prospective series during initial experience

Background

To report the initial experience of surgery for non-functioning pituitary adenoma (NFPA) from a neurosurgeon in a dedicated residency training endoscopic transsphenoidal (ETS) program, and detail the surgical and clinical outcomes during this period.

Methods

A prospective series of all patients operated for NFPA, using an ETS approach, during the three first years of experience of a newly board-certified neurosurgeon was analysed. Clinical, radiological and peri-operative data were collected. Extent of resection (EOR) was determined by formal volumetric analysis. Impact of the learning curve and predictive factors of gross total resection (GTR) were determined.

Results

Fifty-three patients with NFPA were included in this prospective cohort which was divided in two periods of time (“First period”: 30 first cases, and “second period”: 23 following cases). Baseline characteristics of the patients in the two periods were similar. Overall occurrence of complication was 22% and was not significantly different in the two periods of time. No patient had severe neurological complication. Gross total resection was achieved in 70% of patients. Mean Extent of resection was 96%. In a multiple linear regression model, a higher EOR was positively correlated with experience (p = 0.018) and negatively correlated with Knosp Score equal to 4 (p < 0.001). Predictive factors for GTR were Higher Knosp grade (p = 0,01), higher pre-operative volume (p = 0.03), and second period of time (p = 0.01).

Conclusion

NFPA surgery can be safe and efficient during the learning period. Dedicated intensive learning, careful patient selection and multidisciplinary work are key to shorten the learning curve and achieve satisfactory results.

Volumetric Resection and Complications in Nonfunctioning Pituitary Adenoma by Fully Endoscopic Transsphenoidal Approach along 15 Years of Single-Center Experience

Objective  The aim of this study was to evaluate the rate of complications and the extent of resection (EOR) of nonfunctioning pituitary adenomas by endoscopic endonasal approach (EEA) in a 15-year learning curve. Methods  A total of 100 patients operated by the same surgical team were divided chronologically into two, three, and four groups, comparing differences in EOR measured by a semiautomatic software (Smartbrush, Brainlab), rate of immediate postoperative complications, and the visual and hormonal status at 6 months. Results  There were no significant differences over the years in rates of postoperative complications and in visual status at 6 months. A significant linear correlation between the EOR and the number of surgeries (rho = 0.259, p  = 0.007) was found. The analysis was performed in three groups because of the remarkable differences among them; the EOR were: 87.2% (early group), 93.03% (intermediate group), and 95.1% (late group) ( p  = 0.019). Gross total resection was achieved in 30.3, 51.5, and 64%, respectively ( p  = 0.017); also, the rate of reoperation and the worsening of at least one new hormonal axis were worse in the early group. Consequently, the early group had a higher risk of incomplete resection compared with the late group (odds ratio: 4.2; 95% confidence interval: 1.5-11.7). The three groups were not different in demographic and volume tumor variables preoperatively. Conclusions  The first 33 interventions were associated with a lower EOR, a high volume of residual tumor, a high reoperation rate, and a higher rate of hormonal dysfunction. We did not find differences in terms of postoperative complications and the visual status at 6-month follow-up.

Towards ultrahigh resolution OCT based endoscopical pituitary gland and adenoma screening: a performance parameter evaluation

Ultrahigh resolution optical coherence tomography (UHR-OCT) for differentiating pituitary gland versus adenoma tissue has been investigated for the first time, indicating more than 80% accuracy. For biomarker identification, OCT images of paraffin embedded tissue are correlated to histopathological slices. The identified biomarkers are verified on fresh biopsies. Additionally, an approach, based on resolution modified UHR-OCT ex vivo data, investigating optical performance parameters for the realization in an in vivo endoscope is presented and evaluated. The identified morphological features-cell groups with reticulin framework-detectable with UHR-OCT showcase a promising differentiation ability, encouraging endoscopic OCT probe development for in vivo application.

The slope of the learning curve in 600 consecutive endoscopic transsphenoidal pituitary surgeries

BACKGROUND

Endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma has become a mainstay of treatment over the last two decades and it is generally accepted that once this learning curve is achieved, a plateau is reached with little incremental improvement.

OBJECTIVE

The objective of this study was to assess the slope of the learning curve over a long period of time for a variety of outcomes measures.

METHODS

We examined outcomes and complications in a consecutive series of 600 EETS for pituitary adenoma grouped into quartiles based on date of surgery.

RESULTS

GTR significantly increased across quartiles from 55 to 79% in the last quartile (p < 0.005). The rate of intraoperative CSF leak significantly decreased from 60% in the first quartile to 33% in the last quartile and the rate of lumbar drain placement from 28% in the first quartile to 6% in the last quartile (p < 0.005). Hormonal remission for secreting adenomas increased from 68% in the first quartile to 90% in the last quartile (p < 0.05). The rate of post-operative CSF leak trended lower (3% in first quartile to 0.7% in last two quartiles). The greatest improvement in outcome occurred between the first and second quartiles (19.9%), but persistent improvement occurred between the second and third (6.7%) and third and fourth quartiles (8.0%).

CONCLUSION

Although the slope of the learning curve is steeper earlier in a surgeon's experience, the slope does not plateau and continues to increase even over more than a decade.

Sphenoid Sinus Fat Packing in Transsphenoidal Surgery: Long-Term Fate Assessment Using Magnetic Resonance Imaging

Background and Objectives: Following the transsphenoidal approach (TSA), appropriate sphenoid sinus fat packing has been preferred to prevent postoperative cerebrospinal fluid leakage; however, studies on the behavior of fat tissue transplanted in the sphenoid sinus are lacking. This study aimed to determine the long-term fate of these fat grafts using magnetic resonance imaging (MRI).Subjects and Method: A total of 139 postoperative MRI scans of 41 patients who underwent sphenoid sinus fat packing using the standard TSA were evaluated. Additionally, MRI time series indicating the vital fat volumes were assessed postoperatively.Results: In 82.9% of cases, the fat volumes measured in the final MRI scans declined to <20% of the initial volumes; only 4.9% of cases exhibited declines to >60% of the initial volume. The fat tissue volume decreased significantly with time, with a median half-life of 18 months. Typically, the sphenoid sinus was eventually almost filled with air rather than transplanted fat. In the subgroup analysis, the fat clearance rate was significantly lower in patients with residual tumors than in those without such remnants (p=0.013).Conclusion: Long-term MRI surveillance of fat grafts in the sphenoid sinus revealed that the transplanted fat graft had degraded and was gradually eliminated.

Three-Hand Endoscopic Endonasal Transsphenoidal Surgery: Experience With an Anatomy-Preserving Mononostril Approach Technique

BACKGROUND

Variations on the endoscopic transsphenoidal approach present unique surgical techniques that have unique effects on surgical outcomes, extent of resection (EOR), and anatomical complications.

OBJECTIVE

To analyze the learning curve and perioperative outcomes of the 3-hand endoscopic endonasal mononostril transsphenoidal technique.

METHODS

Prospective case series and retrospective data analysis of patients who were treated with the 3-hand transsphenoidal technique between January 2007 and May 2015 by a single neurosurgeon. Patient characteristics, preoperative presentation, tumor characteristics, operative times, learning curve, and postoperative outcomes were analyzed. Volumetric EOR was evaluated, and a logistic regression analysis was used to assess predictors of EOR.

RESULTS

Two hundred seventy-five patients underwent an endoscopic transsphenoidal surgery using the 3-hand technique. One hundred eighteen patients in the early group had surgery between 2007 and 2010, while 157 patients in the late group had surgery between 2011 and 2015. Operative time was significantly shorter in the late group (161.6 min) compared to the early group (211.3 min, P = .001). Both cohorts had similar EOR (early group 84.6% vs late group 85.5%, P = .846) and postoperative outcomes. The learning curve showed that it took 54 cases to achieve operative proficiency with the 3-handed technique. Multivariate modeling suggested that prior resections and preoperative tumor size are important predictors for EOR.

CONCLUSION

We describe a 3-hand, mononostril endoscopic transsphenoidal technique performed by a single neurosurgeon that has minimal anatomic distortion and postoperative complications. During the learning curve of this technique, operative time can significantly decrease, while EOR, postoperative outcomes, and complications are not jeopardized.

A Systematic Review of Secondary Cerebrospinal Fluid Leaks

Background

Secondary cerebrospinal leaks (CSF) are leaks that recur after an initial endoscopic repair of CSF leaks. Identification of characteristics that could predict secondary leaks may allow surgeons to plan repairs with the knowledge that these defects are more likely to fail.

Objective

To identify characteristics that could predict secondary CSF leaks.

Methods

A search of all studies that reported outcomes after endoscopic repair of CSF leaks was conducted by using medical literature data bases. Studies with the following criteria were included: written in the English language, secondary CSF leaks after primary repair, and assessment of success of fistula repair. Data extracted included the etiology of the leak, site of the leak, reconstructive materials used, and success of the repair.

Results

Ninety-four studies, from 1988 to 2015, with a total of 3149 primary CSF leaks were included. Sixty-three studies (67%) had a success rate of ≥80%; 77 studies (82%) had secondary leak rates of <40%. For 88 of the 94 studies (94%), the success rate after secondary repair improved to 81.0–100%. Of 48 studies that included leaks of more than one site, the sphenoid was the most common site of leak in 26 studies (55%), the ethmoid was the most common site in 16 studies (34%), and the cribriform was the most common site in 11 studies (23%).

Conclusion

The rate of secondary CSF leaks was low due to advances in endoscopic repair techniques. Spontaneous and iatrogenic CSF leaks were more likely to recur, especially without adequate control of underlying factors, such as increased intracranial pressure and obesity. Further studies with consistent reporting are required for more definitive conclusions about secondary CSF leaks.

Learning curve of endoscopic pituitary surgery: Experience of a neurosurgery/ENT collaboration

For neurosurgeons, who are accustomed to the binocular microscope, there is a new learning curve that must be overcome for monocular endoscopic pituitary surgery. Different studies describe a learning curve between 15 and 200 procedures, after which both operative time and complications stabilize. In this retrospective study, we evaluate the endoscopic learning curve of our group, already trained in microsurgical transsphenoidal surgery, with the assistance of ear, nose, and throat (ENT) surgeons. From 2010 to 2015, a total of 95 patients with pituitary adenomas were treated with a purely endoscopic approach. The latest 48 patients treated with the endoscope (L group) were compared with the 47 initial patients treated with the endoscope (E group) and with 43 patients treated with the microscope (M group), in terms of surgical time, complications, and tumor removal rate. The complication rate was similar in all the groups, as was the rate of total adenoma resection. Mean surgical time was shorter in the L group than in the E group (115±36min vs. 157±46 min, p<0.001); the average operative time was also shorter in the L group than in the M group (135±43min). The estimated reduction in duration of surgery per 10 patients was 9min (p<0.001). Over time, blood transfusions discrepantly increased from the E group to the L group (11% vs. 31%). Because of the pivotal role of ENT in the transnasal stage of 50 endoscopic procedures, we obtained an operative time comparable to that of microscopic procedures, with similar complication rate and gross total resections. Neurosurgical-ENT combined follow-up proved to be a fundamental protection from late complications.

Factors Affecting the Visual Outcome of Pituitary Adenoma Patients Treated with Endoscopic Transsphenoidal Surgery

OBJECTIVE

To evaluate visual acuity (VA) and visual fields (VF) quantitatively before and after endoscopic transsphenoidal surgery (ETS), with special attention to prognostic factors such as the pituitary adenoma (PA) suprasellar extension (SSE), volume and the patients' age.

METHODS

Medical records of 47 patients with PA undergoing ETS were evaluated. VA, VF, preoperative visual impairment score (VISpre) and postoperative visual impairment score (VISpost) were determined. The PA SSE, volume, chiasmal contact, and their correlation with visual function were assessed preoperatively and postoperatively.

RESULTS

The final cohort included 47 patients. VA improved in 54 of 76 eyes (71.0%) after ETS, and 69 of 76 eyes (90.7%) gained normal VA. Postoperative VF recovery occurred in 32 of 37 eyes (86.5%). The mean change in VIS was 12.0 (95% confidence interval [CI], 7.7-16.3) and improved in all patients with tumor-related visual impairment (n = 25). However, visual outcome was poorer when VISpre was greater than 40. When VISpre was 21-40, age linearly correlated with VIS improvement (P = 0.03); younger patients had satisfactory and older poorer visual outcome. The mean SSE in patients with VF defects (n = 20) was 16.6 mm (95% CI, 13.3-19.9). Mean SSE in patients with no VF defects (n = 23) was 6.6 mm (95% CI, 4.9-8.3; P < 0.001), and the cutoff value for visual perturbations was 9.5 mm for SSE and 8.6 mL for PA volume (P < 0.001 for both).

CONCLUSIONS

The visual outcome after ETS for PAs was excellent, and serious complications were rare. Severe preoperative visual impairment resulted in poorer postoperative visual outcomes. The SSE of the PA was the most important predictor of visual outcome after ETS.

The learning curve in endoscopic endonasal resection of craniopharyngiomas

OBJECTIVE There is a paucity of literature regarding the learning curve associated with performing endoscopic endonasal cranial base surgery. The purpose of this study was to determine to what extent a learning curve might exist for endoscopic endonasal resection in cases of craniopharyngiomas. METHODS A retrospective review was performed for all endoscopic endonasal craniopharyngioma resections performed at Thomas Jefferson University from 2005 to 2015. To assess for a learning curve effect, patients were divided into an early cohort (2005-2009, n = 20) and a late cohort (2010-2015, n = 23). Preoperative demographics, clinical presentation, imaging characteristics, extent of resection, complications, tumor control, and visual and endocrine outcomes were obtained. Categorical variables and continuous variables were compared using a 2-sided Fisher's exact test and t-test, respectively. RESULTS Only the index operation performed at the authors' institution was included. There were no statistically significant differences between early and late cohorts in terms of patient age, sex, presenting symptoms, history of surgical or radiation treatment, tumor size or consistency, hypothalamic involvement, or histological subtype. The rate of gross-total resection (GTR) increased over time from 20% to 65% (p = 0.005), and the rate of subtotal resection decreased over time from 40% to 13% (p = 0.078). Major neurological complications, including new hydrocephalus, meningitis, carotid artery injury, or stroke, occurred in 6 patients (15%) (8 complications) in the early cohort compared with only 1 (4%) in the late cohort (p = 0.037). CSF leak decreased from 40% to 4% (p = 0.007). Discharge to home increased from 64% to 95% (p = 0.024). Visual improvement was high in both cohorts (88% [early cohort] and 81% [late cohort]). Rate of postoperative panhypopituitarism and permanent diabetes insipidus both increased from 50% to 91% (p = 0.005) and 32% to 78% (p = 0.004), which correlated with a significant increase in intentional stalk sacrifice in the late cohort (from 0% to 70%, p < 0.001). CONCLUSIONS High rates of near- or total resection and visual improvement can be achieved using an endoscopic endonasal approach for craniopharyngiomas. However, the authors did find evidence for a learning curve. After 20 cases, they found a significant decrease in major neurological complications and significant increases in the rates of GTR rate and discharge to home. Although there was a large decrease in the rate of postoperative CSF leak over time, this was largely attributable to the inclusion of very early cases prior to the routine use of vascularized nasoseptal flaps. There was a significant increase in new panhypopituitarism and diabetes insipidus, which is attributable to increase rates of intentional stalk sacrifice.

Endoscopic Versus Microscopic Transsphenoidal Approach for Pituitary Adenomas: Comparison of Outcomes During the Transition of Methods of a Single Surgeon

OBJECTIVE

The transition from microscopic to fully endoscopic transsphenoidal surgery requires a surgeon to assess how the change in technique will affect the extent of tumor resection (EOR), outcomes, and complications. We compared a single surgeon's experience transitioning from one technique to the other and examined the operative outcomes and EOR between microscopic versus endoscopic transsphenoidal surgery.

METHODS

Retrospective data analysis of adult patients who were treated surgically for a pituitary adenoma between August 2005 and May 2015 by a single neurosurgeon, who was originally trained and practiced in the microscopic transsphenoidal approach. Patient demographics, perioperative conditions, tumor characteristics, operative times, volumetric EOR, postoperative outcome, and the endoscopic learning curve were evaluated.

RESULTS

One hundred and nine patients underwent microscopic transsphenoidal surgery and 275 patients underwent a fully endoscopic approach. The patient characteristics were similar in the 2 groups. Operative room time was significantly shorter in the endoscopic group than in the microscopic group (180.2 vs. 215.6 minutes; P < 0.001). The endoscopic and microscopic groups had similar volumetric EOR (85.1% vs. 82.8%; P = 0.371) as well as residual tumor volume (1.06 cm³ vs. 1.15 cm³; P = 0.765). The mean length of hospital stay was 2.4 days in the endoscopic group and 3.2 days in the microscopic group (P = 0.03).

CONCLUSIONS

During the transition from the microscopic to the endoscopic approach, similar surgical outcomes and EOR were achieved in the 2 cohorts. In our experience, the endoscopic approach offers the advantage of shorter operative times and lengths of hospital stays after the surgeon has developed more experience with the technique.

A learning curve of endoscopic transsphenoidal surgery for pituitary adenoma

Experience is an important point in the effectiveness of the surgical procedure and in the reduction of complications in pituitary surgery. Endoscopic pituitary surgery differs from microscopic surgery because it requires a steep learning curve for endoscopic skills. In this study, we investigated the learning curve of endoscopic transsphenoidal pituitary surgery in our department. Endoscopic transsphenoidal operations were performed on 80 patients, who were retrospectively examined and grouped as the early and late experience groups to evaluate the learning curve. The patients' characteristics, gross total resection, endocrinological cure, visual field improvement, duration of surgery, postoperative hospital stay, and complications were noted. After examining our patients of the 2 groups of period, our experience showed that as the effectiveness of endoscopic surgery increases, the duration of surgery and postoperative hospital stay decrease. In this study, we identified a learning curve in endoscopic pituitary surgery.

Advantages and limitations of endoscopic endonasal approaches to the skull base

BACKGROUND

The anatomy of the skull base is extremely complex with an abundance of critical neurovascular bundles and their corresponding foramina as well as the insertions and origins of multiple masticatory and craniocervical muscles. These anatomic intricacies increase the difficulty of surgery within this area.

METHODS

Advantages and disadvantages of endoscopic endonasal approaches (EEAs) based on the authors' sequential learning and experience are described.

RESULTS

EEAs offer the advantages of using preexistent air spaces that enable accessing various areas of the skull base, while avoiding external incisions or scars and obviating the need for the translocation of the maxillofacial skeleton. In addition, EEAs are well suited to preserve neurologic, visual, and masticatory functions as well as cosmesis. However, the sinonasal corridor must be expanded and optimized to access the skull base adequately, facilitate the reconstruction of the surgical defect, avoid sinonasal complications, and minimize sequelae. Important considerations can limit or indicate the approach, such as the nature of the pathology, including location, diagnosis, and vascularity; patient characteristics, including age and medical comorbidities; surgeon attributes, including training, experience, and expertise; the resultant need to reconstruct large skull base defects and feasible alternatives to do so; and institutional resources, including adjunctive services, an intensive care unit, and operating room equipment.

CONCLUSIONS

EEAs are important techniques in contemporary skull base surgery. Understanding the indications for and limitations of these approaches help to maximize outcomes.

Endoscopic transnasal approach for removing pituitary tumors

To describe a series of 129 consecutive patients submitted to the resection of pituitary tumors using the endoscopic transsphenoidal approach in a public medical center.

METHOD

Retrospective analysis based on the records of patients submitted to the resection of a pituitary tumor through the endoscopic transsphenoidal approach between 2004 and 2009.

RESULTS

One hundred and twenty-nine records were analyzed. The tumor was non-secreting in 96 (74.42%) and secreting in 33 patients (22.58%). Out of the secretory tumors, the most prevalent was the growth hormone producer (7.65%), followed by the prolactinoma, (6.98%). Eleven patients developed cerebral spinal fluid (CSF) fistulas, and four of them developed meningitis. One patient died due to intracerebral hemorrhage in the postoperative period.

CONCLUSION

The endoscopic transsphenoidal approach to sellar tumors proved to be safe when the majority of the tumors were non-secreting. The most frequent complication was CSF. This technique can be done even in a public hospital with financial limits, since the health professionals are integrated.

Incidence and significance of intraoperative cerebrospinal fluid leak in endoscopic pituitary surgery using intrathecal fluorescein

OBJECTIVE

The true rate of intraoperative cerebrospinal fluid (iCSF) leak during pituitary surgery is not well known because small iCSF leaks are easily missed. Our objective is to determine the rate and significance of iCSF leak in endoscopic pituitary surgery with intrathecal (IT) fluorescein administration and determine factors predictive of iCSF leak.

METHODS

IT fluorescein was administered in 203 consecutive endoscopic, endonasal pituitary surgeries. The rate of iCSF leak was noted prospectively and correlated with tumor diameter and volume, gross total resection, and the learning curve. Postoperative CSF leak rate, complications, and nasoseptal flap utility were also investigated.

RESULTS

The rate of iCSF leak was 61% overall, 44% for tumors<2 cm compared to 72% for tumors≥2 cm and 35% for tumors<1.5 cm3 compared to 68% for those≥1.5 cm3 (P<0.001). Postoperative CSF leak was significantly lower after the first 50 cases (0.7% vs. 10%; P<0.005) with overall leak of 3%. For tumors>2 cm, the introduction of nasoseptal flap reduced the rate of postoperative CSF leak from 5.6% to 1.4%. We did not find any complications clearly related with the use of IT fluorescein.

CONCLUSION

The rate of iCSF leak during endoscopic pituitary surgery using IT fluorescein is higher than previously reported. Tumor diameter and volume are best predictors of the risk of iCSF leak. Based on this knowledge and a closure algorithm that includes a lumbar drain and nasoseptal flap for larger tumors (>2.5 cm), we can conclude that the postoperative CSF leak rate remains exceptionally low, particularly once the learning curve is overcome.

Indications and limitations of endoscopic skull base surgery

A wealth of critical neurovascular structures within a relatively small surface area adds to the already intricate nature of skull base surgery. Surgical approaches to the area are difficult and often associated with significant morbidity and mortality. During the past two decades, endoscopic endonasal approaches (EEAs) have evolved to access the ventral skull base for the resection of tumors (benign and malignant), the decompression of neural structures including the cervicomedullary junction (pannus from rheumatoid arthritis or congenital anomalies, such as platybasia) and the reconstruction of skull base defects (cerebrospinal leaks, meningoencephalocele). These minimal access approaches obviate the need for external incisions, translocation of maxillofacial bones and retraction of the brain. Furthermore, EEAs yield improved visualization, which may reduce complications, and improve quality of life outcomes. Anatomical difficulties (e.g., vascular encasement or extension beyond the plane of a major vessel or cranial nerve), various special conditions (e.g., pediatric patients and vascular tumor) and limitation of institutional resources and technical difficulties may limit the use of EEAs. Thus, one should understand the indications and limitations of EEAs to optimize patient selection, which, in turn, may lead to superior surgical outcomes and reduced morbidity.

Balloon dilation of the eustachian tube in a cadaver model: technical considerations, learning curve, and potential barriers

OBJECTIVES/HYPOTHESIS

The surgical management options for eustachian tube dysfunction have historically been limited. The goal of the current study was to evaluate the technical considerations, learning curve, and potential barriers for balloon dilation of the eustachian tube (BDET) as an alternative treatment modality.

STUDY DESIGN

Prospective preclinical trial of BDET in a cadaver model.

METHODS

A novel balloon catheter device was used for eustachian tube dilation. Twenty-four BDET procedures were performed by three independent rhinologists with no prior experience with the procedure (eight procedures per surgeon). The duration and number of attempts of the individual steps and overall procedure were recorded. Endoscopic examination of the eustachian tube was performed after each procedure, and the surgeon was asked to rate the subjective difficulty on a five-point scale.

RESULTS

Successful completion of the procedure occurred in each case. The overall mean duration of the procedure was 284 seconds, and a mean number of 1.15 attempts were necessary to perform the individual steps. The mean subjective procedure difficulty was noted as somewhat easy. Statistically shorter duration and subjectively easier procedure were noted in the second compared to the first half of the series, indicating a favorable learning curve. Linear fissuring within the eustachian tube lumen without submucosal disruption (nine procedures, 37%) and with submucosal disruption (five procedures, 21%) were noted. The significance of these physical findings is unclear.

CONCLUSIONS

Preclinical testing of BDET is associated with favorable duration, learning curve, and overall ease of completion. Clinical trials are necessary to evaluate safety and efficacy.

Training in neurorhinology: the impact of case volume on the learning curve

This article presents a current view of training in neurorhinology and focuses on the level of evidence for the clinical question of "how many cases are needed to achieve proficiency in endoscopic endonasal skull base surgery?" The authors discuss what defines surgical proficiency, what makes up the learning curve and how it shifts with increasing experience, comparisons of learning curves for different skull base surgeries, and conclude with a discussion and recommendations for achieving high-level proficiency.

Endoscopic transsphenoidal pituitary surgery: evidence of an operative learning curve

BACKGROUND

The use of the fiberoptic endoscope is a recent innovation in pituitary surgery.

OBJECTIVE

To investigate the evidence of an operative learning curve after the introduction of endoscopic transsphenoidal surgery in our unit.

METHODS

The first 125 patients who underwent endoscopic transnasal transsphenoidal surgery for pituitary fossa lesions between 2005 and 2007 performed by 1 surgeon were studied. Changes in a number of parameters were assessed between 2 equal 15-month time periods: period 1 (53 patients) and period 2 (72 patients).

RESULTS

There were 67 patients (54%) with nonfunctioning adenomas, 22 (18%) with acromegaly, and 10 (8%) with Cushing's disease. Between study periods 1 and 2, there was a decrease in the mean duration of surgery for nonfunctioning adenomas (from 120 minutes to 91 minutes; P < .01). This learning effect was not apparent for functioning adenomas, the surgery for which also took longer to perform. The proportion of patients with an improvement in their preoperative visual field deficits increased over the study period (from 80% to 93%; P < .05). There were nonsignificant trends toward improved endocrine remission rates for patients with Cushing's disease (from 50% to 83%), but operative complications, notably the rates of hypopituitarism, did not change. Overall length of hospital stay decreased between time periods 1 and 2 (from 7 to 4 days median; P < .01).

CONCLUSION

The improvements in the duration of surgery and visual outcome noted after about 50 endoscopic procedures would favor the existence of an operative learning curve for these parameters. This further highlights the benefits of subspecialization in pituitary surgery.

Comparative analysis of cost of endoscopic endonasal minimally invasive and sublabial-transseptal approaches to the pituitary

BACKGROUND

Two surgical approaches to the pituitary are commonly used: the sublabial-transseptal (SLTS) approach using microscopy and the endonasal endoscopic minimally invasive (MIPS) approach. Although outcomes are similar for both procedures, MIPS has become increasingly prevalent over the last 15 years. Limited cost analysis data comparing the 2 alternatives are available.

METHODS

A retrospective analysis of cost and volume data was performed using data from the published literature and University of North Carolina at Chapel Hill (UNC) Hospitals. A sensitivity analysis of the parameters was used to evaluate the uncertainty in parameter estimates.

RESULTS

The total cost in real dollars ranges from $11,438 to $12,513 and $18,095 to $21,005 per patient per procedure for MIPS and SLTS, respectively, with a cost difference ranging between $5582 and $9567 per patient per procedure. The sensitivity analysis indicates that the total cost for MIPS is most sensitive to: (1) average length of stay, (2) nursing costs, and (3) number of total complications, whereas the total cost for SLTS is most sensitive to: (1) average length of stay, (2) nursing cost, and (3) operating time. MIPS is less costly than SLTS between 94% and 98% of the time.

CONCLUSION

The results indicate that MIPS is less costly than SLTS at a large academic center. Future research should compare the outcomes and quality of life (QoL) associated with the 2 surgeries to improve the data used to determine the cost-effectiveness of MIPS compared to SLTS.

[Transphenoidal endoscopic approaches for pituitary adenomas: a critical review of our experience]

BACKGROUND

The surgical approach to the pituitary fossae has evolved from transcranial to sublabial and transseptal microscopic ones, up to the current transsphenoidal endoscopic approach.

OBJECTIVES

To present our experience in the transnasal transsphenoidal approach for pituitary adenomas and the modifications introduced to improve tumoral resection and to lower iatrogenia.

MATERIAL AND METHODS

Over nine years, we operated on 37 patients with pituitary adenomas using the transsphenoidal endoscopic approach. We utilised optical lens of 0° (approach) and 30° (adenoma resection), optic navigator, surgical instruments for nasal endoscopic and pituitary surgery. During the neurosurgical step, the endoscope was fixed by an articulated arm. We acceded to the pituitary fossae by a bilateral sphenoidotomy.

RESULTS

Sphenoid pneumatisation was sufficient in all the patients. The more common postoperative complications were diabetes insipidus and endocrinology deficiencies. Postoperative rhinoliquorrhea affected only one patient. No alterations of nasal fossae were observed. Mean patient hospitalisation was five days.

CONCLUSIONS

Transsphenoidal endoscopic approach guided by navigator gives significant advantages: Shorter operating time and fewer complications, greater safety and preservation of the nasal passages. Resecting the sphenoidal rostrum and a fragment of adjacent nasal septum improves surgical instrument management into the pituitary fossae and therefore adenoma resection. Endoscope fixation stabilises the vision and allows the second surgeon to help more effectively.

The role of outcomes data for assessing the expertise of a pituitary surgeon

PURPOSE OF REVIEW

Over the past four decades, advances in surgical technique, instrumentation, and anatomical knowledge have fueled the evolution and sophistication of transsphenoidal pituitary surgery. Paralleling these advances have been major improvements in endocrinological and overall clinical outcomes in patients with pituitary adenomas and other parasellar lesions such as Rathke's cleft cysts and craniopharyngiomas. In this review, we assess the impact of neurosurgeon expertise as a determinant of outcome in pituitary surgery.

RECENT FINDINGS

Published data since the 1980s indicate that remission rates, overall clinical outcomes and surgical complication rates in pituitary and parasellar surgery are related to neurosurgeon practice volume and cumulative clinical experience. More recently, pituitary surgery has been increasingly performed using an endonasal endoscopic approach. Reports over the last decade suggest when an experienced pituitary neurosurgeon performs a fully endoscopic or endoscope-assisted tumor removal; outcomes are similar if not better than when performed by a traditional microscopic transsphenoidal approach.

SUMMARY

A focused clinical practice and large transsphenoidal surgical volume appear to be important outcome determinants for patients with pituitary and parasellar tumors. Strategies that may further improve patient outcomes include establishing guidelines for pituitary tumor centers of excellence and more focused residency and fellowship training in endonasal endoscopic transsphenoidal surgery. Encouraging regionalization of care to higher volume pituitary tumor centers of excellence and promoting patient education on the importance of surgical expertise may further enhance pituitary patient outcomes.

Oronasal complications in patients after transsphenoidal hypophyseal surgery

Transsphenoidal surgery is the most commonly used surgical procedure to handle the hypophyseal region, sometimes associated with oronasal complications.

Material and methods/aim

To evaluate prospectively (specific questionnaire, clinical evaluation) undiagnosed chronic oronasal complications in patients submitted to conventional transsphenoidal adenomectomy surgery, operated at different neurosurgery services more than 6 months ago.

Results

49 patients were evaluated, 37/45 presented macroadenoma. 28,5% were submitted to more than one intervention, 2/5 transsphenoidally. Transsphenoidal approach 92.8% through sublabial route. No patient had spontaneous complaint. With the specific questionnaire 63.2% presented complaints. One patient presented an oronasal fistula, 1 stenosis of the nasal valve area with external nasal deformity. Rhinoscopy detected alterations in 77.5%, nasal endoscopy in 87.7%. Septal perforation was present in 10/12 patients with scabs and 2 with purulent secretion. All 4 patients submitted to 2 transsphenoidal approaches presented septal perforation and nasal synechiae. In the endonasal, synechiae (2), alteration in medium meatus (1) and stenosis of the nasal valve area (1) were observed. Only two patients presented normal evaluation.

Conclusion

A high incidence of nasal complications after conventional transsphenoidal surgery observed through examination and not reported spontaneously point to the need of otorhinolaryngological investigation complemented by nasal endoscopy in patients submitted to procedures through this route.

Endoscopic endonasal transsphenoidal approach through the bilateral nostrils for pituitary adenomas

The endoscopic endonasal transsphenoidal approach through the bilateral nostrils was evaluated for the treatment of pituitary adenoma. The surgical approach is through the bilateral nostrils via minimal or wide dissection of the septal mucosa, depending on the degree of tumor extension. After anterior sphenoidotomy, the endoscope is fixed in one nostril and required instrumentation is inserted in either nostril. In addition, neuronavigation and real-time hormone monitoring are used. Tumor removal rate, endocrinological outcomes, and complications were retrospectively assessed in 194 patients with pituitary adenomas who underwent 213 procedures between December 2001 and March 2008. Greater than 95% resection was achieved in 74 of 131 nonfunctioning adenomas, and the removal rate was significantly higher during 2005-2008 compared to 2002-2004 (p < 0.05). Endocrinological remission was achieved in 20 of 26 growth hormone-secreting tumors of Knosp grades 0-2, 16 of 17 microprolactinomas, and 6 of 9 cases of pure Cushing's disease. Postoperative complications were cerebrospinal fluid leakage in 9 cases, visual worsening in 5, anterior pituitary insufficiency in 5, and permanent diabetes insipidus in 2. The bilateral endonasal approach provides a wide working area without the need for special instrumentation. By modifying mucosal dissection, the endoscopic approach provides flexibility and less invasiveness. The use of neuronavigation or intraoperative hormone monitoring leads to improved surgical results. The present study confirms that this approach is suitable for more extensive sellar tumors.

Comparison of endoscopic and microscopic removal of pituitary adenomas: single-surgeon experience and the learning curve

Object

The endoscopic endonasal approach for resection of pituitary lesions is an effective surgical option for tumors of the sella turcica. In this study the authors compared outcomes after either purely endoscopic resection or traditional microscope-aided resection. They also attempted to determine the learning curve associated with a surgical team converting to endoscopic techniques.

Methods

Retrospective data were collected on patients who were surgically treated for a pituitary lesion at the Hospital of the University of Pennsylvania between July 2003 and May 2008. Age, sex, race, presenting symptoms, length of hospital stay, surgical approach, duration of surgery, tumor pathological features, gross-total resection (GTR) of tumor, recurrence of the lesion, and intraoperative and postoperative complications were noted. All procedures were performed by the same senior neurosurgeon, who was initially unfamiliar with the endoscopic endonasal approach.

Results

A total of 25 patients underwent microscopic resection and 25 patients underwent endoscopic resection performed by a single skull base team consisting of the same senior neurosurgeon and otorhinolaryngologist (M.S.G. and B.W.O.). In the microscopically treated cohort, there were 8 intra- or postoperative complications, 6 intraoperative CSF leaks, 17 (77%) of 22 patients had GTR on postoperative imaging, 5 patients underwent ≥ 2 operations, and 10 (59%) of 17 patients reported total symptom resolution at follow-up. The endoscopically treated group had 7 intraor postoperative complications and 7 intraoperative CSF leaks. Of the patients who had pre- and postoperative imaging studies, 14 (66%) of 21 endoscopically treated patients had GTR; 4 patients had ≥ 2 operations, and 10 (66%) of 15 patients reported complete symptom resolution at follow-up. The first 9 patients who were treated endoscopically had a mean surgical time of 3.42 hours and a mean hospital stay of 4.67 days. The next 8 patients treated had a mean surgical time of 3.11 hours and a mean hospital stay of 3.13 days. The final 8 patients treated endoscopically had a mean surgical time of 2.22 hours and a mean hospital stay of 3.88 days. The difference in length of operation between the first 9 and the last 8 patients treated endoscopically was significantly different. There was a trend toward decreased CSF leaks and other complications from the first 2 groups compared with the third group.

Conclusions

In this subset of patients, the use of endoscopic endonasal resection results in a similar complication and symptom resolution rate compared with traditional techniques. The authors postulate that the learning curve for endoscopic resection can be ≤ 17 procedures.

Minimally invasive pituitary surgery

OBJECTIVES/HYPOTHESIS

Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. The introduction of the endoscope and the advent of minimally invasive pituitary surgery (MIPS) have revolutionized pituitary surgery. This study aims to compile and evaluate outcomes of all of the MIPS performed at our institution.

STUDY DESIGN

Retrospective, cases series of 176 consecutive patients undergoing MIPS.

METHODS

Patient demographics, tumor characteristics, and intraoperative or postoperative complications for of 176 consecutive patients undergoing MIPS were complied. Statistical analysis for categorical variables and incidence across series were conducted using Pearson's chi test and Fisher's exact tests. Odd ratios were calculated to relate the discrete variables to outcomes and designing clinical prediction of risk.

RESULTS

One hundred seventy-six patients who underwent 193 procedures. Pathologic evaluation revealed 147 of the tumors to be pituitary adenomas. Only one death occurred (mortality rate of 0.5%). The rate of diabetes insipidus occurred in 20.2% of the procedures. Vascular complications occurred in 5.2% of the procedures. Intraoperative cerebrospinal fluid (CSF) leaks were identified in 19.7% whereas postoperative CSF leak was noted in 10.3%. Resection of Rathke's cleft cyst correlated higher risk of both intraoperative and postoperative CSF leak (OR = 2.6, P <.001). Resection of tumors other than adenomata correlated with significantly higher risk of CSF leak (OR = 9.0, P = <.001). Sinusitis occurred after eleven resections (5.7%). Meningitis occurred in 2 of 193 resections (1.0%) in our series. Two neurologic complications occurred in our series, pneumocephalus and cranial neuropathy (1.0%). No other complications occurred.

CONCLUSIONS

MIPS is a safe and efficacious marriage of the endoscope to the transsphenoidal approach. Thus, a brightness and clarity of vision is combined with the unique ability to explore the tumor bed with angled views and hydroscopy. Outcomes and complication rates comparable to traditional transsphenoidal approaches have resulted but with less dissection and tissue manipulation, reduced need for packing, and greater patient comfort and acceptance.

Endoscopic skull base surgery

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field.

PREDICTORS AND INCIDENCE OF CENTRAL DIABETES INSIPIDUS AFTER ENDOSCOPIC PITUITARY SURGERY

OBJECTIVE

With the advent of minimally invasive endoscopic pituitary surgery, there has been concern that the technique may be associated with higher rates of complications such as diabetes insipidus (DI) than traditional approaches, particularly early in a center's experience. We report the incidence and predictors of diabetes insipidus in patients after endoscopic transnasal resection (minimally invasive pituitary surgery) of pituitary lesions.

METHODS

Data were collected from hospital and clinic records on the first 119 consecutive patients undergoing endoscopic pituitary surgery at our center.

RESULTS

The rate of postoperative diabetes insipidus is low in patients undergoing minimally invasive pituitary surgery (permanent, 2.7%; transient, 13.6%). Factors associated with development of DI after minimally invasive pituitary surgery include Rathke's cleft cyst histology, intraoperative cerebrospinal fluid leak, and previous nonendoscopic lesion resection. Elevated serum sodium (&gt;145 mmol/L) within the first 5 days postoperatively has a high sensitivity (87.5%), specificity (83.5%), and negative predictive value (99.5%) for permanent postoperative DI development.

CONCLUSION

Transitioning from microscopic to endoscopic pituitary surgery can be achieved with a low incidence of DI. An elevated serum sodium level in the first 5 postoperative days using standard monitoring can predict the chance of developing permanent DI. Patients having no elevated serum sodium measurements, defined as &gt;145 mmol/L, in the first 5 days postoperatively will rarely, if ever, develop permanent DI, thereby validating short postoperative inpatient stays with minimal risk of readmission for DI management. Those with a single serum sodium measurement greater than 145 mmol/L have a 15% risk of developing permanent DI.

Acesso endoscópico transnasal aos tumores selares

A cirurgia dos tumores selares é tradicionalmente um campo de atuação dos neurocirurgiões. O uso do endoscópio permitiu acesso transnasal direto ao seio esfenoidal sem a necessidade de descolamento do septo nasal, com menor desconforto e morbidade pós-operatória inferior aos métodos tradicionais. OBJETIVO: Verificar as dificuldades técnicas, intercorrências e complicações pós-operatórias, no manejo otorrinolaringológico do acesso endoscópico transnasal à sela túrcica. MATERIAL E MÉTODO: Foram analisados retrospectivamente os prontuários dos pacientes submetidos à cirurgia da região selar, entre março de 2001 e dezembro de 2005. Foram incluídos 91 pacientes submetidos a um total de 95 procedimentos por via transnasal endoscópica. Desenho científico: Clínico retrospectivo. RESULTADOS: Foi possível a realização da técnica endoscópica transnasal em todos os pacientes estudados. Não houve necessidade de remoção da concha média ou de desvios septais em nenhum dos casos. A principal intercorrência foi fístula liquórica durante a remoção de tumores (13,68%). As complicações pós-operatórias foram: sangramento nasal (8,42%), fístula liquórica (8,42%), e meningite (2,11%). CONCLUSÃO: O acesso endoscópico transnasal aos tumores selares pôde ser realizado de forma minimamente invasiva, preservando-se as estruturas nasais nos 95 procedimentos estudados, independente da idade do paciente, características e etiologia do tumor.

Endoscopic transnasal approach to sellar tumors

Transsphenoidal surgery for sellar region tumors is traditionally done only by neurosurgeons. The use of endoscopes has permitted a direct transnasal approach to the sphenoidal sinus, without dissection of the septal mucosa, reducing postoperative morbidity.

Aim

The purpose of this study was to assess the technical difficulties, and per and postoperative complications of the otolaryngological management of the endoscopic transnasal approach to the sellar region.

Material and Method

159 patients undergoing sellar region surgery between March 2001 and December 2006 were assessed retrospectively. 91 patients who underwent 95 endoscopic transnasal procedures were included in this study. Study design: a clinical retrospective study.

Results

The endoscopic transnasal technique was feasible for every patient, independent of age, anatomical variations, tumor characteristics, tumor etiology, and previous surgical history. There was no need to remove the middle turbinate or septal deviations in any of the cases. The most significant peroperative complication was CSF leak during tumor removal (13.68%). Postoperative complications were: nasal bleeding (8.42%), CSF leak (8.42%), and meningitis (2.19).

Conclusion

The transnasal endoscopic approach was accomplished with minimal invasion, preserving nasal structures in all 95 procedures, independent of age, anatomical variations, tumor characteristics, tumor etiology, and previous surgical history..

The learning curve in pancreatic surgery

BACKGROUND

Pancreatic surgery is technically complex. We hypothesized that a learning curve existed for pancreaticoduodenectomy even for surgeons who had completed their training.

METHODS

During 1990 to 2004, we studied 650 consecutive patients who underwent pancreaticoduodenectomy by 3 surgeons who began their attending careers at 1 center. Operative time, estimated blood loss (EBL), length of hospital stay (LOS), and the status of resection margins (for pancreatic adenocarcinoma) were analyzed. The chi2, independent t test and Mann-Whitney U test were used to evaluate differences in categorical, normally distributed continuous, and non-normally distributed continuous variables, respectively. Using serial groups of 30 cases, median operative time, EBL, and LOS were calculated and the trend over time modeled using third-order polynomial equations. Trends in retroperitoneal margin positivity (R0/R1) were assessed.

RESULTS

From the first 60 cases per surgeon to the second 60 cases per surgeon, the median EBL dropped (1100 vs 725 mL, P < .001), operative time decreased (589 vs 513 minutes, P < .001), and LOS decreased (15 vs 13 days, P = .004). The proportion of microscopically positive or suspicious margins also decreased from the surgeons' first 60 cases each to the second 60 cases (30% vs 8%, P < .001). Extended analysis of a single surgeon's cases suggested that additional experience provided further incremental improvement (P < .001).

CONCLUSIONS

Pancreaticoduodenectomy has an inherent learning curve. After 60 cases, surgeons achieved significantly decreased EBL, operative time, and LOS, and carried out more margin-negative resections. Improvement in measured outcomes continues during the operative career.

The learning curve in pancreatic surgery

BACKGROUND

Pancreatic operation is technically complex. We hypothesized that a learning curve existed for pancreaticoduodenectomy even for surgeons who had completed their training.

METHODS

During 1990 to 2004, we studied 650 consecutive patients who underwent pancreaticoduodenectomy by 3 surgeons who began their attending careers at 1 center. Operative time, estimated blood loss (EBL), length of hospital stay (LOS), and the status of resection margins (for pancreatic adenocarcinoma) were analyzed. The chi(2), independent t test and Mann-Whitney U test were used to evaluate differences in categoric, normally distributed continuous, and non-normally distributed continuous variables, respectively. Using serial groups of 30 cases, median operative time, EBL, and LOS were calculated and the trend over time modeled using third-order polynomial equations. Trends in retroperitoneal margin positivity (R0/R1) were assessed.

RESULTS

From the first 60 cases per surgeon to the second 60 cases per surgeon, the median EBL dropped (1100 vs 725 mL, P < .001), operative time decreased (589 vs 513 minutes, P < .001), and LOS decreased (15 vs 13 days, P = .004). The proportion of microscopically positive or suspicious margins also decreased from the surgeons' first 60 cases each to the second 60 cases (30% vs 8%, P < .001). Extended analysis of a single surgeon's cases suggested that additional experience provided further incremental improvement (P < .001).

CONCLUSIONS

Pancreaticoduodenectomy has an inherent learning curve. After 60 cases, surgeons achieved significantly decreased EBL, operative time, and LOS, and carried out more margin-negative resections. Improvement in measured outcomes continues during the operative career.

Transnasal endoscopic surgery of the pituitary: modifications and results over 10 years

OBJECTIVE

A 10-year retrospective review of three endoscopic approaches used by the authors for pituitary gland surgery is presented. We review our results and complications and outline the advantages and disadvantages of each. The variations in nasal anatomy that factor in the endoscopic approach are tabulated and discussed.

METHODS

A chart review and examination of computed tomography and magnetic resonance imaging scans of patients who have had endoscopic pituitary surgery by the authors was performed. We gathered specific details of the operative approach, nasal-sinus anatomy, tumor location, required ancillary nasal procedures, and postoperative complications.

RESULTS

Ninety patients had endoscopic pituitary surgery. Operative reports and review of radiographic studies were possible for 75 patients. The surgical approach progressed over 10 years from endoscopic transseptal (42) to bilateral transostial (13) to unilateral transostial (20). Adequate exposure for the degree of resection was achieved in all patients. Complications included hemorrhage requiring return to the operating room (1), transient visual field loss (2), and transient diabetes insipidus (7). Four patients subsequently had craniotomy to resect suprasellar tumor extension. The average follow-up was 6 years. One patient required revision endoscopic resection 3 years later for tumor recurrence. Anatomic findings included nasal septal deflections in 36 (48%) of the patients, abnormalities of the turbinates in 42 (56%), and variances of the sphenoid sinus septum in 59 (79%) of the patients. In the unilateral transostial approach, the operative side was often determined by anatomic factors.

CONCLUSION

The authors have exclusively used endoscopic surgery of pituitary gland tumors for over 10 years. Modifications to the approach have occurred as a result of increased surgeon experience and improved technology. The unilateral transostial approach is safe, effective, and recommended.

Bibliography. Current world literature. Nose and paranasal sinuses

PURPOSE OF REVIEW

Patients with advanced head and neck cancer are being treated with chemo-radiotherapy, and life is being prolonged, with or without persistent disease, for longer than was previously. Hypercalcaemia may present in patients with advanced or disseminated head and neck cancer, and, as such, these patients may present to a larger variety of clinicians for advice concerning their symptoms and illness. Modes of presentation of hypercalcaemia and treatment strategies are reviewed.

RECENT FINDINGS

There were previously few large series of head and neck cancer patients diagnosed with hypercalcaemia, which may or may not have been related to their cancer being treated. Investigations, by way of blood/serum calcium level, may identify such patients. Patients with cancer-related hypercalcaemia have a poor prognosis, but many may respond temporarily to treatment when offered, with an improvement of their quality of life and death.

SUMMARY

Hypercalcaemia should and must be considered in all patients who have or possibly have a diagnosis of a head and neck cancer and who present unwell with symptoms of fatigue, lethargy and somnolence. Investigation must include serum calcium (corrected for serum albumin binding) and parathyroid hormone level. Patients may be treated by a combination of rehydration and bisulphonate therapy until the serum calcium is reduced to a level below 3 mmol/l. The majority of patients diagnosed with hypercalcaemia due to head and neck malignancy die of their diseases in the short term, but some may enjoy a prolongation of life with reasonable quality if diagnosed and treated aggressively.

The learning curve in endoscopic pituitary surgery and our experience

Experience is the important point in reduction of the complications and in the effectiveness of the surgical procedure in pituitary surgery. Endoscopic pituitary surgery differs from microscopic surgery, since it requires a steep learning curve for endoscopic skills. In this article, we evaluate our learning curve in two groups, as early and late experience. Purely endoscopic transsphenoidal operations were performed on 78 patients, which were retrospectively reviewed and grouped as early and late experience groups. We used the purely endoscopic endonasal approach to the sella that was performed via an anterior sphenoidotomy, without the use of a transsphenoidal retractor. All patients with adenomas were evaluated considering operation time, endocrinology, ophthalmology, total removal and, especially, modifications of standard technique. On the basis of the experience gained with the use of the endoscope in transphenoidal surgery over the years, modifications can be performed on the different phases of the endoscopic approach. Reviewing our cases in two groups of period due to our experience showed that the effectiveness of endoscopic surgery increases and operation time decreases. In our study, we identified a learning curve in endoscopic pituitary surgery.